Thermally responsive circuit breaker for electric cigar lighter



AUS 19, 1959 J. l.. BOUDREAU 3,462,721-

THERMALLY RESPONSIVE CIRCUIT BREAKER FOR ELECTRIC CIGAR LIGHTER Filed March 25, 1968 un' l J I 1 l 11 United States Patent O M THERMALLY RESPONSIVE CIRCUIT BREAKER FOR ELECTRIC CIGAR LIGHTER John L. Boudreau, Stratford, Conn., assignor to Casco Products Corporation, Bridgeport, Conn., a corporation of Connecticut Filed Mar. 25, 1968, Ser. No. 715,741

Int. Cl. H01h 71/16 U.S. Cl. 337-75 1 Claim ABSTRACT F THE DISCLUSURE A cigar lighter receptacle having a circuit breaker at its rear end comprising a heat-responsive member which is responsive to excessive heat to open a circuit to a resilient input terminal and thus to the heating element of the lighter, the heat-responsive member being resettable through the open end of the receptacle by the use of a rod extending through the receptacle and a passage leading to said resilient input terminal.

This invention relates to a cigar lighter, and more particularly to a receptacle for the igniting unit having an overload and short circuit responsive circuit breaker.

An object of this invention is to provide a simple circuit breaker which is attached to the inaccessible rear end of the receptacle and which is capable of being reset from the open end of the receptacle when the igniting unit is removed therefrom.

In the accompanying drawings:

FIGURE 1 is a longitudinal sectional view of a cigar lighter receptacle and circuit breaker showing the igniting unit in open circuit or storage position-the circuit breaker being in closed circuit position.

FIG. 2 is a longitudinal sectional view of the receptacle and circuit breaker, with the circuit breaker in open circuit position, and in dotted lines a rod extending through the open end of the receptacle from which the igniting unit had been removed to position to rest the circuit breaker.

FIG. 3 is a sectional view showing the circuit breaker before it is attached to the receptacle.

FIG. 4 is a cross section taken on the line 44-4 of FIG. 3.

As shown in the accompanying drawings, the cigar lighter receptacle of the present invention comprises a receptacle for an igniting unit 11 which has a heating element 12 adapted to be brought to incandescence by engagement of a contact member 13 thereon wit-h energized bmetallic latch Ilingers 14 that hold the igniting unit when connected therewith in energizing position until the fingers 14 respond to the heat from the heating element, whereupon the ingers 14 release the igniting unit which is returned by a spring (not shown) to open circuit position for removal and use.

The receptacle 10 has a rear wall 15 which is engaged by a block 16 of insulating material on which the latch fingers 14 are secured by an elongate threaded member 17 having a headed portion engaging the fingers and a nut 18 which, through the interposition of a washer 19 and insulating disk 20, secure the member 17, lingers 14 and block 16 to the rear wall 15 of the receptacle.

The circuit breaker 21 of the present invention comprises a housing 22 having an inner wall 23 and an outer wall 24, both of insulating material, connected by a shell 25 which may be metallic. The inner wall 23 is mounted on a threaded sleeve 26 which is screwed on the threaded member 17 until it engages the nut 18, as shown in FIGS. 1 and -2.

The outer wall 24 of the housing carries an input ter- ICC minal 27 connected as usual to the ungrounded side of a battery or other source of current. Secured to the outer Wall 24 by the input terminal 27 is a U-shaped resilient spring 28 having a leg 29 forming a contact member and extending diametrically across the space in the housing which is usually circular. Adapted to cooperate with the contact leg 29 of the spring 28 to close the circuit to the bmetallic latch lingers 14 is a bmetallic heatresponsive resilient contact 30 which has one leg 31 secured to the threaded sleeve 26 and the other leg 32 free and extending toward the outer wall 24. The leg 32 is provided with a V-shaped end 33 positioned to engage and disengage the end of the leg 29 connected to the input terminal 27.

In its unstressed condition, the end of the leg 29 stands clear of the V-shaped end 33 of the bmetallic contact 28, as shown in FIG. 2, and maintains the circuit to the latch fingers 14 open. In normal position of use, however, the leg 29 is stressed to the right, as shown in FIGS. 1 and 4, where it is engaged and held by the outer portion 34 of the V-shaped end 33 of the contact 28. The circuit to the fingers 14 is thus closed, and the stiffness of the contact 28 and the angle of engagement of the portion 34 with the end of the leg 29 are sutiicient to prevent the end of the leg 29 of the contact 28 from displacing the leg `32 of the bimetal contact 30 and moving to open-circuit position.

However, should excessive heat be developed in the receptacle as a result of some malfunctioning of the igniting unit or its operation or of the bmetallic ngers 14 of the receptacle, or a short circuit being established between the tingers 14 and the receptacle parts which are grounded, the heat is transmitted through the elongate member 17 and the sleeve 26 to the leg 32 of the contact 30, which deforms due to its bmetallic construction, and allows the leg 29 of the contact 28 to pass the V-shaped end 33 of the contact and assume the open circuit position shown in FIG. 2.

As soon as the circuit is thus broken, the parts begin to dissipate the excessive heat and the contact 30 returns to its normal position shown in FIGS. 1 and 2. However, in this position, it is spaced from the end of the leg 29 of the contact 28 and the circuit remains open until it is manually reset after the cause of the malfunctioning has been removed.

Cigar lighters of the type disclosed herein are usually mounted in such positions on instrument panels and other parts of an automobile that the rear end of the receptacle is inaccessible or difficult to reach in order to reset a circuit breaker mounted on or at the rear end of the receptacle. Accordingly, it is an object of the present invention to provide a circuit breaker with a minimum number of parts which can be readily reset from the open front end of the receptacle.

To accomplish this, the present invention instead of being provided as a solid rod or stud, the elongate member 17 is formed so as to have a tubular passage 35 open at both ends, and the leg 29 of the contact 28 is positioned to have a part of its surface aligned with the open rear end of the member 17. With this arrangement, when it is desired to reset the circuit breaker, it is merely necessary to remove the igniting unit from the receptacle and pass a thin rod-like element S, such as a stick of wood, plastic or the like, through the receptacle and the passage 35 until it engages the leg 29, and continue the movement until the top of the leg 29 passes under the V-shaped portion 33 of the leg 32 of the contact 30 to the closed circuit position shown in FIG. l in which it remains until and unless the receptacle again becomes overheated.

FIGS. 3 and 4 show the circuit breaker portion of the present invention separately from the receptacle, and this circuit breaker as so made may be applied to a receptacle, as shown in FIG. 1, as a replacement for the initially installed circuit breaker should that become defective.

As usual, the receptacle is provided with a threaded rearward extension 36 which is interposed between the disk 20 and the rear wall 15 of the receptacle to receive the threaded end 37 of a sleeve 38 which is used to clamp the front flanged end of the receptacle to the instrument panel 39.

Variations and modifications may be -made within the scope of the claim and portions of the improvements may be used without others.

II claim:

1. A cigar lighter receptacle comprising a tubular body having an open front end and at the rear end a bottom wall; a block of insulating material engaging the front side of the bottom wall; heat-responsive latch ingers engaging said block; means for securing the block and latch Afingers to the bottom wall including an elongate threaded member and a nut on said threaded member; a housing having a threaded sleeve in threaded engagement with said threaded member to be supported thereby coaxially with the receptacle, said housing having an inner end wall carried by said threaded sleeve and an outer end wall; an input terminal mounted on said outer end wall and insulated from said housing, said terminal carrying a resilient leaf spring in axially spaced relation thereto; and a -bimetallic contact member mounted on said threaded sleeve in heat-conducting relation and electrical engagement with said heat-responsive latch fingers through the medium of said elongate member, said contact member being positioned to normally engage and hold said resilient leaf spring in current-conducting position, said leaf spring being biased to move in the direction of the open end of the receptacle and disengage said contact member when the latter becomes excessively heated, said elongate member having a longitudinal passage open at both ends, and said resilient leaf spring being positioned opposite the open inner end of said passage whereby the resilient leaf spring may be moved from open circuit position to closed circuit position to be reengaged and held by said bimetallic contact member by force applied to said leaf spring by an elongate article inserted into and extending through the open end of the receptacle and said tube.

References Cited UNITED STATES PATENTS 3,012,120 12/ 1961 Gaudet 337-75 3,230,345 1/ 1966 Horwitt 219-265 3,238,353 3/1966 Lybrook 219-265 3,248,502 4/ 1966 Lybrook 337-103 VOLODYMYR Y. MAYEWSKY, Primary Examiner U.S. Cl. X.R. 

